Arduino I2C 扫描器

当我们在做一些用到 I2C 总线连接的设计，经常苦恼无法确定 I2C 是否连接正确，主从设备是否可以正常通信，这时候我们可以通过下面这个例程，来测试主机是否能找到从设备，需要用到 Arduino Wire 库。

#include<Wire.h>
void setup()
{
	Wire.begin();
	Serial.begin(9600);
	Serial.println("====== I2C Scanner Getting Started");
}

void loop()
{
	byte error, address;
	int nDevices;
	Serial.println("Scanning...");
	nDevices = 0;
	for(address = 1; address < 127; address++ )
	{
		Wire.beginTransmission(address);
		error = Wire.endTransmission();
		if (error == 0)
		{
			Serial.print("I2C device found at address 0x");
			if (address<16)
				Serial.print("0");
				Serial.print(address,HEX);
				Serial.println("  !");
			nDevices++;
		}
		else if (error==4)
		{
			Serial.print("Unknow error at address 0x");
			if (address<16)
				Serial.print("0");
				Serial.println(address,HEX);
			}
		}
		if (nDevices == 0)
			Serial.println("No I2C devices found\n");
		else
			Serial.println("done\n");
		delay(5000);// wait 5 seconds for next scan
	}
}